Coffee Equipment; Why You Should Never Touch the Edge of Your Portafilter

When you start learning about coffee, the first thing you get is that every step in the process, even the smallest, is incredibly important. A wrong move or technique in the grinding process will affect how well you can compress the coffee, a bad compression will affect how the coffee flows, how the coffee is poured, how it will affect the taste, etc. you get the point.

One of these little steps that has a big impact on the overall #coffee making process is to tap the rim of your #portafilter during compression. This technique was taught in workshops, cafes, and courses until the last few years, when people began to realize that it wasn't a great thing. Some baristas still practice this technique today - unknowingly holding themselves back from constantly getting perfect shots.

Here is the reason; Touching the side of your portafilter causes channeling. When you touch the edge, the response from the coffee is to create a small separation wall from the portafilter, which creates a channel for the water to pass through, rather than distributing the water and pressure evenly over the entire coffee shot.

If you haven't heard the term 'channel' before, let's explain it a bit more. To get the perfect #espresso shot you simply place the portafilter on the group head and run the shot where the excess pressure and water is released, you pull the coffee from the grinders in the basket straight into your mug. However – water is lazy and will choose the path of least resistance when it has the opportunity, and one of those opportunities is through channeling. When there is a void in your coffee it grinds, the water instantly flows into that cavity because that means it puts less pressure on it and has to do less work. It provides an uneven extraction because this water and pressure only goes into the cavity and not to the other parts of the coffee, so what you will find in your cup is actually just hot water.

To sum it up – don't touch the side of your portafilter as this will cause channeling and prevent you from getting great shots. Try to break this habit and you are likely to see improvements quickly!